This document discusses cervicogenic headache, including its definition, pathophysiology, diagnosis, characteristics, differential diagnosis, and interventions. Cervicogenic headache is a secondary headache caused by a physical or neurological condition in the cervical spine. It is characterized by unilateral or bilateral pain that begins in the neck and radiates outward. Diagnosis involves taking a history, physical exam, and diagnostic tests or blocks to determine the source of pain in the cervical spine. Potential interventions include injections of local anesthetics or steroids into affected nerves or using radiofrequency ablation.